1. Field of the Invention
The invention relates to a laser oscillator which is provided with a laser medium flow path for circulating a laser medium.
2. Description of the Related Art
Known in the art is a laser oscillator which is provided with folding mirrors which are arranged on a path of laser light between two discharge tubes wherein the flow of laser medium is prevented from ending up stagnating near the folding mirrors (for example, see Japanese Patent Publication No. 63-239888A and Japanese Patent Publication No. 2010-171145A).
In a laser oscillator including a plurality of discharge tubes, if the distributions of pressure of the laser medium in the discharge tubes differ from each other, the laser power of the generated laser light may become unstable. Therefore, a technique is desired which can circulate the laser medium without stagnation while making the pressures of the laser medium in a plurality of discharge tubes constant.